The harbour town of Omis is situated on the Cetina estuary about 26km south-east of Split, on the Poljica coastline. During the thirteenth and fourteenth centuries, it was a refuge for pirates (Omiski gusari) who used their speedy Sagittae (“arrow”) ships to plunder freighters in the estuary. After their attacks, they quickly withdrew back upriver where the freighters and their escorts were unable to pursue them.